| Message ID | c9889cf5f7a3d101ef380905900b45a182596f56.1549896081.git-series.maxime.ripard@bootlin.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/sun4i: dsi: Add burst mode support | expand |
Hi, On Mon, 2019-02-11 at 15:41 +0100, Maxime Ripard wrote: > The Allwinner BSP makes sure that we don't end up with a null start delay > or with a delay larger than vtotal. > > The former condition is likely to happen now with the reworked start delay, > so make sure we enforce the same boundaries. > > Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> > --- > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > index 9471fa695ec7..506f2e8cf454 100644 > --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > @@ -358,8 +358,12 @@ static u16 sun6i_dsi_get_video_start_delay(struct sun6i_dsi *dsi, > struct drm_display_mode *mode) > { > u16 start = clamp(mode->vtotal - mode->vdisplay - 10, 8, 100); > + u16 delay = mode->vtotal - (mode->vsync_end - mode->vdisplay) + start; > > - return mode->vtotal - (mode->vsync_end - mode->vdisplay) + start; > + if (delay > mode->vtotal) > + delay = delay % mode->vtotal; I wonder whether delay == mode->vtotal would make sense at all. If not, then we can just apply the modulo unconditionally. But in doubt, let's keep things this way. Cheers, Paul > + > + return max_t(u16, delay, 1); > } > > static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi,
hi, On Tue, Feb 12, 2019 at 04:30:33PM +0100, Paul Kocialkowski wrote: > Hi, > > On Mon, 2019-02-11 at 15:41 +0100, Maxime Ripard wrote: > > The Allwinner BSP makes sure that we don't end up with a null start delay > > or with a delay larger than vtotal. > > > > The former condition is likely to happen now with the reworked start delay, > > so make sure we enforce the same boundaries. > > > > Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> > > Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> Thanks! > > --- > > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > index 9471fa695ec7..506f2e8cf454 100644 > > --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > @@ -358,8 +358,12 @@ static u16 sun6i_dsi_get_video_start_delay(struct sun6i_dsi *dsi, > > struct drm_display_mode *mode) > > { > > u16 start = clamp(mode->vtotal - mode->vdisplay - 10, 8, 100); > > + u16 delay = mode->vtotal - (mode->vsync_end - mode->vdisplay) + start; > > > > - return mode->vtotal - (mode->vsync_end - mode->vdisplay) + start; > > + if (delay > mode->vtotal) > > + delay = delay % mode->vtotal; > > I wonder whether delay == mode->vtotal would make sense at all. If not, > then we can just apply the modulo unconditionally. But in doubt, let's > keep things this way. I guess that situation can happen, especially with the start clamping. But even without it, it can happen when mode->vtotal - mode->vsync_end (so the backporch) is equal to 10. Maxime
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c index 9471fa695ec7..506f2e8cf454 100644 --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c @@ -358,8 +358,12 @@ static u16 sun6i_dsi_get_video_start_delay(struct sun6i_dsi *dsi, struct drm_display_mode *mode) { u16 start = clamp(mode->vtotal - mode->vdisplay - 10, 8, 100); + u16 delay = mode->vtotal - (mode->vsync_end - mode->vdisplay) + start; - return mode->vtotal - (mode->vsync_end - mode->vdisplay) + start; + if (delay > mode->vtotal) + delay = delay % mode->vtotal; + + return max_t(u16, delay, 1); } static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi,
The Allwinner BSP makes sure that we don't end up with a null start delay or with a delay larger than vtotal. The former condition is likely to happen now with the reworked start delay, so make sure we enforce the same boundaries. Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com> --- drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)